[virtio-dev] RE: [virtio-comment] [PATCH v4 2/8] transport-pci: Refer to the vq by its number

[Parav Pandit <parav@nvidia.com>]

> From: Max Gurtovoy <mgurtovoy@nvidia.com>
> Sent: Monday, March 27, 2023 6:49 PM
> 
> > diff --git a/content.tex b/content.tex index 1ab7794..0f634ac 100644
> > --- a/content.tex
> > +++ b/content.tex
> > @@ -321,7 +321,7 @@ \section{Virtqueues}\label{sec:Basic Facilities of a
> Virtio Device / Virtqueues}
> >   VIRTIO_F_IN_ORDER feature. If negotiated, this knowledge
> >   might allow optimizations or simplify driver and/or device code.
> >
> > -Each virtqueue is identified as vq number or also referred
> > +Each virtqueue is identified by a vq number or also referred
> >   to as a virtqueue number; vq number range is from 0 to 65535.
> >
> 
> Please squash this to patch 1/8 were you introduced this line.
> 
Latest v7 doesnt have this wrong hunk here.

> 
> 
> >   Each virtqueue can consist of up to 3 parts:
> > diff --git a/transport-pci.tex b/transport-pci.tex index
> > b07a822..044c085 100644
> > --- a/transport-pci.tex
> > +++ b/transport-pci.tex
> > @@ -390,13 +390,15 @@ \subsubsection{Common configuration structure
> > layout}\label{sec:Virtio Transport
> >
> >   \item[\field{queue_notify_data}]
> >           This field exists only if VIRTIO_F_NOTIF_CONFIG_DATA has been
> negotiated.
> > -        The driver will use this value to put it in the 'virtqueue number' field
> > -        in the available buffer notification structure.
> > +        The driver will use this value to put it in the field
> > +        \field{vqn} in the available buffer notification
> > +        structure.
> 
> why do you add new lines here and bellow ?
>
Will fix in v8.
Below line addition is due to existing limit of 64 or 65 chars per line.
 
> >           See section \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-
> specific Initialization And Device Operation / Available Buffer Notifications}.
> >           \begin{note}
> >           This field provides the device with flexibility to determine how
> virtqueues
> >           will be referred to in available buffer notifications.
> > -        In a trivial case the device can set \field{queue_notify_data}=vqn. Some
> devices
> > +        In a trivial case the device can set
> > +        \field{queue_notify_data}=vq number. Some devices
> >           may benefit from providing another value, for example an internal
> virtqueue
> >           identifier, or an internal offset related to the virtqueue number.
> >           \end{note}
> > @@ -1005,7 +1007,7 @@ \subsubsection{Device
> Initialization}\label{sec:Virtio Transport Options / Virti
> >   The driver typically does this as follows, for each virtqueue a device has:
> >
> >   \begin{enumerate}
> > -\item Write the virtqueue index (first queue is 0) to \field{queue_select}.
> > +\item Write the virtqueue number (first queue is 0) to \field{queue_select}.
> >
I noticed mentioning of first queue here which is not related.
Similar cleanup that Stefano suggested.
Fixing this in v8 too.

> >   \item Read the virtqueue size from \field{queue_size}. This controls how big
> the virtqueue is
> >     (see \ref{sec:Basic Facilities of a Virtio Device /
> Virtqueues}~\nameref{sec:Basic Facilities of a Virtio Device / Virtqueues}). If
> this field is 0, the virtqueue does not exist.
> > @@ -1035,7 +1037,7 @@ \subsubsection{Available Buffer
> > Notifications}\label{sec:Virtio Transport Option
> >
> >   When VIRTIO_F_NOTIFICATION_DATA has not been negotiated,
> >   the driver sends an available buffer notification to the device by
> > writing -the 16-bit virtqueue index
> > +the 16-bit virtqueue number
> >   of this virtqueue to the Queue Notify address.
> >
> >   When VIRTIO_F_NOTIFICATION_DATA has been negotiated, @@ -1053,7
> > +1055,7 @@ \subsubsection{Available Buffer Notifications}\label{sec:Virtio
> Transport Option
> >   If VIRTIO_F_NOTIF_CONFIG_DATA has been negotiated:
> >   \begin{itemize}
> >   \item If VIRTIO_F_NOTIFICATION_DATA has not been negotiated, the
> > driver MUST use the -\field{queue_notify_data} value instead of the
> virtqueue index.
> > +\field{queue_notify_data} value instead of the virtqueue number.
> >   \item If VIRTIO_F_NOTIFICATION_DATA has been negotiated, the driver
> MUST set the
> >   \field{vqn} field to the \field{queue_notify_data} value.
> >   \end{itemize}
> 
> In general, after fixing the above minor comments - looks good.
> 
> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>

Thanks. Will add your RB in v8 for this patch.